The Iranian nuclear deal, finalized between Teheran and six world powers on April 2, 2015, is two years old. While people's memories of the diplomatic triumph over what had become a dangerous nuclear issue are still fresh, the landmark deal now faces uncertainties because of the changing stance of the United States, which played an important role in making it reality.

US President Donald Trump, from his campaign trail days, has been saying he plans to "dismantle" the deal. And analysts say that even though he may not be able to scrap a multilateral deal, he can find ways to "violate" it, which in turn will make it difficult for the US to uphold it.

On March 23, Republican Senator Bob Corker submitted a bill titled Countering Iran's Destabilizing Activities Act to the US Senate Foreign Relations Committee, which had received more than a dozen co-sponsors in just a few days. The bill could allow Trump to re-impose sanctions on Iran, including those set to expire under the Iranian nuclear deal by adding new conditions that must be met before Washington lifts the sanctions on certain Iranian parties.